Evan,
Warmer air will hold much more moisture than cooler air so you would look toward keeping the ambient conditions warm.
A unit of moisture found in a unit of warm air results in a much lower RH than that same amount of moisture in cool air.
You can look at a psychometric chart to see this relationship.
Moisture will always move to balance the relative humidity between the concrete and the surrounding air. So by keeping the air warm you lower its RH, and draw moisture from the slab more quickly than if the air were cool and had a correspondingly higher RH.